BioQuakes

AP Biology class blog for discussing current research in Biology

Month: February 2012 (Page 2 of 2)

CHIPping away at Disease

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On February 27, 2012

In Student Post

Photo Credit: ngineerit flickr

Many people suffer from chronic illnesses that require daily, even hourly, injections of medication. These injections can be frustrating, annoying, and dangerous. However, after 15 years of work, MIT professors Robert Langer and Michael Cima finally created a microchip that can be implanted once and can distribute dosages of medicine for extended periods of time. The device delivers the same dosages as the injections. In fact, Cima and Langer found that the chip delivered the dosages at a more consistent and accurate rate than the injections.

The chip would be a major help to people who need injections of medicine because it wouldn’t give them any reason, such as pain, to skip their dose. The chip can be implanted in about 30 minutes and in a trial study there were no side effects. They implanted seven women from 65 years of age to 70 years of age who suffer from osteoporosis. The chip diligently delivered their medicine for four months. This new technology can be expanded to deliver several medications for longer periods of time. It could save millions of people from daily pain.

Koalas in danger

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On February 27, 2012

In Student Post

We all know that species have been going extinct when faced with threats such as climate change, reduced habitat and diseases. A recent New York Times article reveals one such species that people have realized is in danger is the koala. Besides the loss of habitat and climate changes in Australia, a new bacterium has been found in wild koalas called chlamydia.

There are two strains now known which have been affecting the koala population in Queensland. The first is Chlamydia pecorum and the second is C. pneumoniae. The bacteria are transmitted through mating and birth and possibly fighting. Some of the symptoms are eye infections, which can lead to blindness that will make it hard for them to find eucalyptus leaves, respiratory infections, and cysts that cause female koalas to be infertile.

The bacteria is growing so much in the area of Queensland since many of the koalas there are infected with koala retrovirus which acts like H.I.V. in koalas making their immunes system shut down. There is no way to treat the retrovirus but researchers are trying to create a vaccine to prevent the spread of chlamydia. There is no set plan on how to distribute the vaccine yet but they are still trying to figure out what the most efficient method of vaccination will be after tests have been completed.

from single cell to multi-cellular

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On February 27, 2012

In Student Post

Have you ever wondered how single cellular organism evolved into multicellular organisms? In a recent New York Times article, some scientists decided to see if they could get single cellular organisms to somehow evolve into multicellular ones. The problem that they thought of was that in multicellular organisms there are many cells which die so that the entire organism can live on. Why single cell organisms would group together with other single cell organisms just to die for the new multicellular organism was puzzling.

They designed an experiment where they had yeast in flasks of broth where they were being shaken for a day and then left alone for the yeast to settle. Then a drop of the settled yeast was taken and transferred to a new flask where the yeast could continue to grow. This process was continued and would allow the yeast which had evolved to be the densest and to settle furthest down to be carried to the next flask. after a few weeks the scientists observed that the yeast was falling faster and was becoming cloudy at the bottom. When looked at under the microscope the scientists found that the yeast had evolved into snowflake shaped clumps of hundreds of yeast cells stuck together. These cells were not just unrelated clumps since when separated individually, cells would recreate these snowflake shaped clumps. This property of clusters of single celled organisms to make a multicellular like organism is not special to yeast. Another organism called choanoflagellates is a single celled organism that also exhibits these traits.

One of the more amazing parts about this was that to reproduce, branches of the snowflake clump would break off after growing too large. When looked at closer they found that a section of the cells near the branch commit suicide to separate the branch to allow it to grow into a new clump. Being able to create multicellular organisms that had cells willing to commit suicide for the rest of the organism in a matter of weeks was amazing and could mean that the history of single celled organisms evolving into multicellular ones might not be as complicated as previously thought. Even though this form of natural selection was done in flasks, the natural environment could have preferred multicellular organisms over single cellular organisms for a number of reasons.

The Sad Fate Of Salmon

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On February 17, 2012

In Student Post

 

Picture of Salmon - Free Pictures - FreeFoto.com

http://www.freefoto.com/preview/09-07-3/Salmon

Often times we are encouraged to consume more fish for their nutritious Omega-3 fats.  One species of fish “Salmon” is most often touted for its high omega-3 content.  Salmon is particularly prevalent in US supermarkets and is consumed by approximately 25% of Americans.  It is however curious to note that 90% of salmon consumed by American’s is in fact farm-raised.  These farmed raised fish in comparison to their wild relatives contain 20% less omega-3 fats, 20% lower protein content, hefty doses of antibiotics, dye; to mimic the healthy orange color of wild salmon, flame retardants, and pesticides which exist in their feed.

 

Recently there has been much debate about approving the farming and distribution of Genetically engineered salmon throughout the United States.  The modified salmon in question is being studied by the largest salmon farming business in the US; Aqua Bounty Farms.  “This experimental hatchery has been injecting growth hormone genes into fertilized salmonid eggs to produce fast growing salmon, trout and Arctic char.”.  In response, Purdue University and the National Academy of Sciences has produced their own research that highlights the considerable risks of such genetic modification.  Research from the mentioned institutions states that releasing one of these “transgenic”  fish into the wild could damage native populations to the point of extinction.

 

This brings us to the next question, what are the odds one of these transgenic fish will escape to surrounding waters?  A statement from the Canadian government provides a dark answer.  “In the past decade nearly 400,000 farmed-raised Atlantics escaped into British Columbian waters and began competing with wild species for food and habitat”.  Even more sinister is the fact that these are mild predictions, environmental experts put the figure closer to 1,000,0000 escapes.

 

As of now the USDA (hyperlink) which in the past has advocated clear marking of food as organic or genetically modified has curiously lent Aqua Bounty Farms $500,000 and declared their approval of GMO salmon.  Last year the FDA gave the go-ahead for the GMO fish despite considerable evidence that it may very well endanger Wild Salmon.  Luckily Congress shows no signs of approving the sale of such fish at this present moment.

 

References

 

http://www.nicholas.duke.edu/thegreengrok/salmon2008/?searchterm=None

 

http://www.whfoods.com/genpage.php?tname=george&dbid=96

 

http://www.purdue.edu/uns/html4ever/0002.Muir.trojan.html

 

http://www.fda.gov/newsevents/publichealthfocus/ucm224089.htm

GO TO SLEEP!

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On February 15, 2012

In Student Post

Photo Credit: mont3rros4

We all know that sleep deprivation causes the brain to become exhausted, but  a recent new study has shown that sleep deprivation causes nerve cells to become increasingly jumpy.

 

Most of us these days don’t get enough sleep. But sleep deprivation can cause people to have seizures and hallucinations. People believe that sleep deprivation lowers a person’s alertness, but Marcello Massimini from the University of Milan and his fellow colleagues have discovered that the brain actually becomes more reactive as hours awake accumulate.

Six people were gathered and did not sleep for a whole day. Massimini gave each person a jolt of magnetic current to the participants skull. The nerve cell received an electrical response and Massimini was able to measure the strength of the electrical response. He did this to the patients twice. Once right after they woke up from sleep and once after they hadn’t sleep for a whole day. The results were that the patients had a stronger electrical response after they hadn’t slept for a whole day than when they just woke up.

The theory is that the brain accumulates connection as the person learns new things. Sleep clears the brain of extra information and leaves only the most important information and connections. These enhanced excitability could be the explanation of why people have seizures after they haven’t slept in a whole day. Also doctors have induced seizures on patients by keeping them up all night. New studies are being tested if wether sleep deprivation can lead to reversing depression since the brain has a heightened excitement without sleep.

Other effects of sleep deprivation are stress, memory impairment, and poor quality of life. It is advisable for teenagers and adults to get about 8-9 hours of sleep. Now lets get some sleep!

That’s Disgusting!

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On February 1, 2012

In Student Post

Some Rights Reserved. More Information: www.flickr.com/photos/sugarpond/2602585958/

 

Have you ever watched something so gross you just have to make a face?
Scientists are studying disgust and how it may have helped us evolve into a clean, healthy, and surviving race.

Disgust isn’t just a learned behavior, as I assumed. It begins very early- as you can see on the faces of  these babies who are eating lemons for the first time. And the grammar school taunting of “you have cooties” is a hurtful taunt because the labeling evokes a small sense of disgust in the other children toward the child being teased. It is the disgust, and to a very small degree, the feeling of being shunned that creates the kindergarten tears.

Though teasing puts disgust in a negative light, it has done wonders for the human race.  According to Dr. Valerie Curtis from the London School of Hygiene and Tropical Medicine:

“[Disgust] is in our everyday life. It determines our hygiene behaviors. It determines how close we get to people. It determines who we’re going to kiss, who we’re going to mate with, who we’re going to sit next to. It determines the people that we shun, and that is something that we do a lot of.”

In other words, disgust partially defines who we spend time with, how we maintain ourselves and who we do not spend time with. Because we have a sense of disgust, we humans have kept ourselves clean enough to thrive in this bacteria filled world. Pregnant women are especially sensitive to disgust, especially in the first trimester, when fetal development is most fragile. It is also the time when the mothers immune system is the least strong. For these reasons, the mother’s emotional way of warding off disease — disgust —  is strengthened.

The emotion of disgust stems manly from the insula and amygdala. The insula, a “prune sized,” centrally located “slab of brain tissue,” causes many of the social emotions, including guilt, pride, and humiliation. The amygdala, similarly, is connected to human emotional responses, especially fear and pleasure.

Since disgust has show to be such a key factory in our motivation to stay clean, and healthy, Dr. Valerie Curtis (quoted above) along with other pubic health activists have been “trying to gross people out” in the name of hygiene. Through cartoons and pubic advertisements, the activists are aiming to invoke a sense of disgust in the current, unclean practices. The programs currently exist in Africa, India and England. Who knew disgust could be so helpful?

Main Article:

http://www.nytimes.com/2012/01/24/science/disgusts-evolutionary-role-is-irresistible-to-researchers.html?pagewanted=1&_r=2&ref=science

More Information:

1. https://sites.google.com/site/jasonanthonyclark/evolution-of-disgust-2012

2. http://rstb.royalsocietypublishing.org/site/2011/behavioural_disease_avoidance.xhtml

 

 

 

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